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Asphalt Plants


BREDL comments on DRAFT Air Permit for Smith & Sons Paving Company, McDowell County.

Comments of Louis Zeller
NC Division of Air Quality Public Hearing
February 8, 2001

DRAFT Air Permit No. 08979R00
Smith & Sons Paving Company, McDowell County
Site No. 1/56/00183

General comments

Thank you for the opportunity to comment on this draft permit. I have read the pertinent documents associated with this permit including the application for permit, the permit review, and the draft permit. Based on my analysis, The DAQ should deny this permit.

An epidemiological study should be undertaken by the DAQ so that we may better determine the health effects of human exposure to asphalt fumes. Based on our experience working with residents living near asphalt plants, we must conclude that the skin rashes, difficulty breathing, asthma, and cancer clusters associated with living near these plants constitute a public health problem of unknown magnitude. It is hard to believe that all these problems are due solely to careless plant operators who lack concern for their neighbors. Rather, it is the responsibility of the state agencies charged with protecting public health to take action to reduce known sources of death and disease.

The DAQ’s use of the SCREEN3 model for toxic, ground level (fugitive) emissions remains troublesome since all such dispersion models do not apply within the atmospheric boundary layer, a distance of 30 feet from the ground where frictional effects predominate. This means that the use of SCREEN3 will predict more dispersion and lower pollutant levels than will actually occur. To the extent that acceptable ambient limits (AALs) are designed to protect human health, the use of the dispersion model in this case gives the wrong result. Other air dispersion studies, based on average factors from EPA’s AP-42, show that ambient air quality standards are often exceeded for arsenic, cadmium and other heavy metals and for organic chemicals such as benzene and formaldehyde. With almost 2,000 dangerous chemicals in asphalt fume, it is important that the decision to build an asphalt plant in a populated valley prone to inversions not be based on a model which was developed solely for smokestack emissions, not boundary layer fugitive emissions.

Specific Comments

1) The permit does not control odorous emissions

Under Specific Conditions and Limitations A.5, the draft permit states,

As required by 15A NCAC 2D .0522 "Control and Prohibition of Odorous Emissions," the Permittee shall not cause, allow, or permit any source to be operated without employing suitable measures for the control of nuisance odors.


However, state law prohibits operation of a plant without suitable measures to control odorous emissions. The DAQ permit Review states that, “It is a subjective determination as to whether this facility will comply with the regulation.” Generally speaking, odor may be a subjective phenomenon determined by individual acuity and tolerance. However, the stated purpose of 2D .0522 is “to provide for the control and prohibition of odorous emissions.” [2D .0522 (a)]. It states further that, “This regulation shall apply to all operations that produce odorous emissions.” [2D .0522 (b)] (emphases added) As written, this draft permit fails to stipulate what measures are suitable for the control of odors. Further, the permit review reveals that the division has no objective means to determine compliance, or whether the plant will even meet permit requirements. As a practical matter, the DAQ inspector who might respond to a plant neighbor’s complaint about odor would have no means of enforcing this regulation. This is an omission which must be corrected before the permit is issued.

2) Air pollution is underestimated

The draft permit Specific Condition A.12 lists regulated emission sources ES-1 asphalt drum mixer, ES-2 storage silos, and ES-3 silo truck loading. Attachment 1 to the permit also lists Activities Exempted from Permitting Under 15A NCAC 2Q .0102. The officially exempted sources include: 1) a No.2 fuel oil fired asphalt tank heater, and 2) a fuel oil storage tank. The attachment acknowledges that the asphalt tank heater is a source of toxic air pollutants and Title V criteria pollutants, and that the storage tank is a source of criteria pollutants. Omitted from either permit list are the following: 1) mobile sources of diesel exhaust, 2) material handling and road dust, and 3) fugitive emissions from loaded trucks prior to departure to the job site. A recent EPA report lists all the above sources with corresponding emissions of criteria pollutants and hazardous air pollutants. I have attached Table 2 from the December 2000 EPA Hot Mix Asphalt Plants Emission Assessment Report to these remarks. The DAQ’s omission of so many known air pollution sources from the permit should be corrected. The true total of toxic air emissions should be included in the determination of whether the plant meets the required acceptable ambient limits.

I plan to submit further comments.